12 JAN 2012 by ideonexus
The Origin of Life is Speculative
The question of the origin of life is essentially speculative. We have to construct, by straightforward thinking on the basis of very few factual observations, a plausible and self-consistent picture of a process which must have occurred before any of the forms which are known to us in the fossil record could have existed. 1 
notes
notesWe have no fossil record of the origin of life, we are left only to attempt to recreate it in the lab, but we won't know if we got the process right.
21 SEP 2011 by ideonexus
Evolution Threatens Creationists Sense of Values
At this point I could simply say, “I’ve given the evidence, and it shows
that evolution is true. Q.E.D.” But I’d be remiss if I did that, because, like
the businessman I encountered after my lecture, many people require
more than just evidence before they’ll accept evolution. To these folks,
evolution raises such profound questions of purpose, morality, and
meaning that they just can’t accept it no matter how much evidence they
see. It’s not that we evolved from apes that bother... 1 notes
notesResistance to evolution is less about the theory and more about its moral implications.
20 SEP 2011 by ideonexus
Evolution in the Laboratory Occurs Very Quickly
One approach is to compare the rates of evolution in the fossil record
with those seen in laboratory experiments that used artificial selection, or
with historical data on evolutionary change that occurred when species
colonized new habitats in historical times. If evolution in the fossil
record were much faster than in laboratory experiments or colonization
events—both of which involve very strong selection—we might need to
rethink whether selection could explain changes in fossils. But ...Folksonomies: evolution experimentation
Folksonomies: evolution experimentation
1 notes
notesSo quickly in fact that scientists could turn an elephant into a mouse in just 10,000 years.
16 SEP 2011 by ideonexus
Birds to Reptiles
Because reptiles appear in the fossil record before birds, we can guess
that the common ancestor of birds and reptiles was an ancient reptile,
and would have looked like one. We now know that this common ancestor
was a dinosaur. Its overall appearance would give few clues that it was
indeed a “missing link”—that one lineage of descendants would later give
rise to all modern birds, and the other to more dinosaurs. Truly birdlike
traits, such as wings and a large breastbone for anchoring ...Folksonomies: evolution
Folksonomies: evolution
1 notes
notesBirds and reptiles share many resemblances, meaning they have a common ancestor, which is dinosaurs.
16 SEP 2011 by ideonexus
DNA as Evidence of Common Ancestry
By sequencing
the DNA of various species and measuring how similar these sequences
are, we can reconstruct their evolutionary relationships. This is done
by making the entirely reasonable assumption that species having more
similar DNA are more closely related—that is, their common ancestors
lived more recently. These molecular methods have not produced much
change in the pre-DNA-era trees of life: both the visible traits of organisms
and their DNA sequences usually give the same informatio... 1 notes
notesThe idea of common ancestry leads naturally to powerful and testable predictions about evolution.
19 MAY 2011 by ideonexus
Species Divisions are Complicated
Zoologists have traditionally divided the vertebrates into classes: major divisions with
names like mammals, birds, reptiles and amphibians. Some zoologists, called 'cladists',* insist that a
proper class must consist of animals all of whom share a common ancestor which belonged to that
class and which has no descendants outside that group. The birds would be an example of a good
class. All birds are descended from a single ancestor that would also have been called a bird and
would have sha...
1 The ancestors are birds are reptiles, but in the fossil record where do we draw the line between them?
